Tuta Mail

Details

The service provided is not open source, or source available, but just the email clients provided are provided under a GPLv3 license, not the service itself.

Tuta has a history of marketing themselves as an “open source email service”. Even on their homepage, they used to state:

[…] making Tuta the best open source email service all-around.

They have stated they’re aiming to open source their server side elements also, but this does not appear to have been achieved 6 years after mentioned there.

They continue to advertise Tuta mail as open source in their marketing and on their blog. When questioned on their social post, Tuta provided the following response:

Hi there! Thanks for your feedback. We plan to open source our server side as well but right now it is not because: With the client code being open source, everybody can build the client themselves, run it locally and verify that the open source code is being used. If we published the server code open source, this would not be the case: No one would be able to verify that the open source server code is actually running on our server - so publishing it is a bit pointless.

This response ignores the issue of misleading marketing, while only considering some of the benefits of open source.

Tuta appears to be funded from grants and from selling its mail & calendar services.